You were sitting in Mattheo's lap while Mattheo was talking to his other Slytherin friend's. Mattheo looks down at you to see how your doing but you were just playing with his rings and he smiles slightly

Mattheo: Do you want one, love?

Mattheo takes your hand and slips a ring on your finger. Mattheo has always been cold and angry but he has an exception for you (his gf) because your his.

After he slips the ring on he goes back to talking with his friend's